The Vikings were the only NFL team that had one receiver catch twice as many passes as anyone else on the roster. That's not a distinction they hope to repeat.

Harvin is a dynamic talent who should get as many touches as humanly possible. He can't carry the load by himself, however. He needs help from the rest of the Vikings receiver corps, but with the season opener fast approaching, it's anyone's guess who will step forward and fill that void.

Jerome Simpson is capable of providing that speedy vertical threat, but he won't be available the first three games while he serves an NFL-mandated suspension. In his absence, the Vikings need others to pick up the slack, take pressure off Harvin and provide second-year quarterback Christian Ponder a reliable target.

Who, though? That's still unknown and should be a growing cause for concern. The Vikings have Harvin, Simpson and who else? A few have shown brief flashes, but nobody has exactly distinguished himself, at least not to the degree that inspires much confidence.

The auditions continued Friday night against San Diego in the third preseason game, but the regular-season dress rehearsal offered more mistakes and ineptitude than clarity by the first-team offense in a 12-10 loss.

The only thing worse than the Vikings offense in the first half was the performance by the NFL's replacement referees. Memo to NFL Commissioner Roger Goodell: Please finalize a new labor deal with your referees association, pronto. The incompetence displayed by the replacement crew dispatched to the Metrodome on Friday was beyond embarrassing.

Actually, the entire first half was a dreadful mess. The Vikings held out Simpson because they wanted to take a long look at their young receivers, but the offense struggled to establish anything productive.

Publicly, the Vikings have expressed faith in their receivers, and they're certainly in a better spot now than last season. Simpson alone guarantees that. So far, he has been a model teammate and employee in the locker room since arriving with off-the-field baggage.

Simpson's track record suggests he'll be inconsistent, but his physical skills are undeniable. He possesses big-play capability and -- as he revealed in hurdling a Bills defender last week -- he occasionally produces spectacular moments.

If this training camp is any indication, Ponder will lean heavily on his tight ends, primarily Kyle Rudolph. Those two have developed a close rapport on and off the field, and tight end is an integral component of offensive coordinator Bill Musgrave's system.

That's not enough, though. The Vikings need to find more options and better depth at receiver.

Jenkins is the most logical candidate, but he's 30 and missed the final five games last season because of a knee injury. Jenkins recently agreed to a $1.5 million pay cut, lowering his base salary to $1 million, which presumably improved his chances of securing a roster spot. That's hardly a vote of confidence.

Jenkins is a big target, but he lacks top-end speed to create separation. Ponder targeted Jenkins on the first two third-down attempts Friday. The first pass sailed wide, the second one went through his hands as he came out his break.

The Vikings would love to see a few of their younger receivers separate themselves, whether it's Devin Aromashodu, Stephen Burton, Emmanuel Arceneaux or Jarius Wright. That hasn't happened yet.

Aromashodu averaged 18 yards per catch last season, but he's wildly inconsistent. He didn't catch a pass in the first two preseason games, prompting the coaching staff to blame some of his ineffectiveness on bad luck and poor throws. He caught three passes for 28 yards in the second half Friday, which can be viewed as a positive sign only if he continues to build on that.

"We're still trying to determine which guy is going to step up and be that replacement [for Simpson]," coach Leslie Frazier said. "I don't think we can say we answered that tonight."

That better happen soon. The regular season and Simpson's suspension are closing in fast. Percy Harvin is a terrific player, but he can't do it alone.